U.S. patent application number 12/090565 was filed with the patent office on 2008-11-13 for apparatus for plasma reaction and system for reduction of particulate materials in exhaust gas using the same.
This patent application is currently assigned to Korea Institute of Machinery & Materials. Invention is credited to Min-suk Cha, Kwan-tae Kim, Dae-hoon Lee, Jae-ok Lee, Young-hoon Song.
Application Number | 20080276600 12/090565 |
Document ID | / |
Family ID | 38997380 |
Filed Date | 2008-11-13 |
United States Patent
Application |
20080276600 |
Kind Code |
A1 |
Lee; Dae-hoon ; et
al. |
November 13, 2008 |
Apparatus for Plasma Reaction and System for Reduction of
Particulate Materials in Exhaust Gas Using the Same
Abstract
A reduction system for particulate materials in exhaust gas,
which is connected to a tailpipe of an engine that burns a
hydrocarbon-based fuel supplied from a fuel storage tank, and
collects and removes particulate materials within the exhaust gas,
may include a plasma reactor having a gas inlet and an outlet, and
a DPF (diesel particulate filter) trap having a filter. The
tailpipe of the engine may communicate with the gas inlet of the
plasma reactor, and the outlet of the plasma reactor may
communicate with the DPF trap. The exhaust gas exhausted from the
engine may be transferred to the DPF trap after being heated while
passing through the plasma reactor.
Inventors: |
Lee; Dae-hoon;
(Daejeon-city, KR) ; Kim; Kwan-tae; (Daejeon-city,
KR) ; Song; Young-hoon; (Daejeon-city, KR) ;
Cha; Min-suk; (Daejeon-city, KR) ; Lee; Jae-ok;
(Daejeon-city, KR) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Korea Institute of Machinery &
Materials
Yuseong-gu
JP
|
Family ID: |
38997380 |
Appl. No.: |
12/090565 |
Filed: |
July 12, 2007 |
PCT Filed: |
July 12, 2007 |
PCT NO: |
PCT/KR2007/003394 |
371 Date: |
April 17, 2008 |
Current U.S.
Class: |
60/286 ; 60/275;
60/311 |
Current CPC
Class: |
F01N 3/025 20130101;
F01N 2240/28 20130101 |
Class at
Publication: |
60/286 ; 60/275;
60/311 |
International
Class: |
F01N 3/025 20060101
F01N003/025; F01N 3/01 20060101 F01N003/01; F01N 3/027 20060101
F01N003/027 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 27, 2006 |
KR |
10-2006-0104786 |
Aug 1, 2006 |
KR |
10-2006-0072721 |
Dec 15, 2006 |
KR |
10-2006-0128415 |
Claims
1. A reduction system for particulate materials in exhaust gas,
which is connected to a tailpipe of an engine that burns a
hydrocarbon-based fuel supplied from a fuel storage tank, and
collects and removes particulate materials within the exhaust gas,
the reduction system comprising: a plasma reactor having a gas
inlet and an outlet; and a DPF (diesel particulate filter) trap
having a filter, wherein the tailpipe of the engine communicates
with the gas inlet of the plasma reactor and the outlet of the
plasma reactor communicates with the DPF trap, and wherein the
exhaust gas exhausted from the engine is transferred to the DPF
trap after being heated while passing through the plasma
reactor.
2. The reduction system of claim 1, wherein the plasma reactor
comprises: a body including a reaction chamber having the gas inlet
and the outlet and a base formed at the lower end of the reaction
chamber, the base including a mixing chamber communicating with the
gas inlet and communicating with the reaction chamber via an inflow
hole; and an electrode protruding into the reaction chamber while
being supported by the base and being spaced apart from the inner
surface of the reaction chamber.
3. The reduction system of claim 2, wherein a fuel inlet is formed
on the base of the body and a heating chamber is formed in the
electrode, the heating chamber communicating with the mixing
chamber and the fuel inlet being connected to the heating
chamber.
4. The reduction system of claim 3, wherein a fuel injector is
provided to the fuel inlet, the fuel injector being fixed on the
base of the body.
5. The reduction system of claim 3, wherein a heat exchanging
conduit is formed in a wall body of the reaction chamber to
communicate the gas inlet with the mixing chamber, the heat
exchanging conduit being spiral in form along a circumference of
the reaction chamber.
6. The reduction system of claim 3, wherein the inflow hole is
formed on the inner surface of the reaction chamber to skew off at
an angle to a normal line of the inner surface of the reaction
chamber, and wherein mixed fuel formed by mixing gas and fuel in
the mixing chamber flows into the reaction chamber through the
inflow hole while forming a rotational flow and circulates around a
circumference of the electrode.
7. A reduction system for particulate materials in exhaust gas,
which is connected to a tailpipe of an engine that burns a
hydrocarbon-based fuel supplied from a fuel storage tank, and
collects and removes particulate materials in the exhaust gas, the
reduction system comprising: a plasma reactor having an inlet for
gas and an outlet; and a DPF (diesel particulate filter) trap
having a filter, wherein the tailpipe of the engine is branched off
and communicated with the DPF trap and the inlet for gas of the
plasma reactor, respectively, and the outlet of the plasma reactor
is communicated with the tailpipe that connects the engine and the
DPF trap, and wherein a part of the exhaust gas exhausted from the
engine is transferred to the DPF trap after being heated while
passing through the plasma reactor.
8. The reduction system of claim 7, wherein the plasma reactor has
a fuel inlet and the fuel inlet is connected to the fuel storage
tank, and wherein fuel injected through the fuel inlet is
plasma-reacted in the reaction chamber together with the exhaust
gas flowing in through the gas inlet, such that the fuel is
reformed to a pre-oxidation material that may be oxidized at a
relatively low temperature in comparison with the exhaust gas, or
burned to raise the temperature of the exhaust gas, and is
transferred to the DPF trap.
9. The reduction system of claim 8, wherein the pre-oxidation
material includes hydrogen or carbon monoxide.
10. The reduction system of claim 8, wherein the plasma reactor
comprises: a body including a reaction chamber having the gas inlet
and the outlet and a base formed at the lower end of the reaction
chamber, the base including a mixing chamber communicating with the
gas inlet and communicating with the reaction chamber via an inflow
hole; and an electrode protruding into the reaction chamber while
being supported by the base and being spaced apart from the inner
surface of the reaction chamber, wherein the fuel inlet is formed
on the base of the body and a heating chamber is formed in the
electrode, the heating chamber communicating with the mixing
chamber and the fuel inlet being connected to the heating
chamber.
11. The reduction system of claim 10, wherein a heat exchanging
conduit is formed in a wall body of the reaction chamber to
communicate the gas inlet with the mixing chamber, the heat
exchanging conduit being spiral in form along a circumference of
the reaction chamber.
12. The reduction system of claim 10, wherein the inflow hole is
formed on the inner surface of the reaction chamber to skew off at
an angle to a normal line of the inner surface of the reaction
chamber, wherein mixed fuel formed by mixing gas and fuel in the
mixing chamber flows into the reaction chamber through the inflow
hole while forming a rotational flow and circulates around a
circumference of the electrode.
13. The reduction system of claim 10, wherein a fuel supply conduit
fixed to the base of the body is fitted to the fuel inlet, and a
gas supply conduit is fitted to a side of the fuel supply conduit
while communicating with each other, thereby spraying the fuel
supplied through the fuel supply conduit into the heating chamber
with the gas supplied through the gas supply conduit.
14. A reduction system for particulate materials in exhaust gas,
which is connected to a tailpipe of an engine that burns a
hydrocarbon-based fuel supplied from a fuel storage tank, and
collects and removes particulate materials in the exhaust gas, the
reduction system comprising: a plasma reactor having a inlet for
gas and an outlet; and a DPF (diesel particulate filter) trap
having a filter, wherein the tailpipe of the engine communicates
with the DPF trap and the outlet of the plasma reactor communicates
with the tailpipe that connects the engine and the DPF trap, and
the plasma reactor has a fuel inlet and the fuel inlet is connected
to the fuel storage tank, wherein fuel injected through the fuel
inlet is plasma-reacted in the reaction chamber such that the fuel
is reformed to a pre-oxidation material that may be oxidized at a
relatively low temperature in comparison with the exhaust gas, or
burned to raise the temperature of the exhaust gas, and is
transferred to the DPF trap.
15. The reduction system of claim 14, wherein the plasma reactor
comprises: a body including a reaction chamber having the gas inlet
and the outlet and a base formed at the lower end of the reaction
chamber, the base including a mixing chamber communicating with the
gas inlet and communicating with the reaction chamber via an inflow
hole; and an electrode protruding into the reaction chamber while
being supported by the base and being spaced apart from the inner
surface of the reaction chamber.
16. The reduction system of claim 15, wherein the fuel inlet is
formed on the base of the body and a heating chamber is formed in
the electrode, the heating chamber communicating with the mixing
chamber and the fuel inlet being connected to the heating
chamber.
17. The reduction system of claim 15, wherein the inflow hole is
formed on the inner surface of the reaction chamber to skew off at
an angle to a normal line of the inner surface of the reaction
chamber, wherein a mixed fuel formed by mixing gas and fuel in the
mixing chamber flows into the reaction chamber through the inflow
hole while forming a rotational flow and circulates around a
circumference of the electrode.
18. The reduction system of claim 15, wherein a heat exchanging
conduit is formed in a wall body of the reaction chamber to
communicate the gas inlet with the mixing chamber, the heat
exchanging conduit being spiral in form along a circumference of
the reaction chamber.
19. A reduction system for particulate materials in exhaust gas,
which is connected to a tailpipe of an engine that burns a
hydrocarbon-based fuel supplied from a fuel storage tank, and
collects and removes particulate materials in the exhaust gas, the
reduction system comprising: a plasma reactor having a inlet for
gas and an outlet; and a DPF (diesel particulate filter) trap
having a filter, wherein the tailpipe of the engine communicates
with the DPF trap and the outlet of the plasma reactor communicates
with the tailpipe that connects the engine and the DPF trap,
wherein the plasma reactor comprises a body including a reaction
chamber having the gas inlet and the outlet and a base formed at
the lower end of the reaction chamber, the base including a mixing
chamber communicating with the gas inlet and communicating with the
reaction chamber via an inflow hole, an electrode protruding into
the reaction chamber while being supported by the base and being
spaced apart from the inner surface of the reaction chamber, a
first fuel injector being fitted to a first fuel inlet formed on
the base of the body and spraying liquid fuel into the mixing
chamber, and a second fuel injector being fitted to a second fuel
inlet connected to the reaction chamber and spraying liquid fuel
into the reaction chamber.
20. The reduction system of claim 19, wherein a heating chamber is
formed in the electrode, the heating chamber communicating with the
mixing chamber and the first fuel inlet being connected to the
heating chamber, such that the first fuel injector sprays liquid
fuel into the heating chamber.
21. The reduction system of claim 19, wherein the second fuel
injector is fitted to skew off at an angle to the inner surface of
the reaction chamber on the side thereof, and sprays and supplies
liquid fuel above the electrode inside the reaction chamber.
22. The reduction system of claim 19, wherein the first fuel
injector and the second fuel injector are connected to the fuel
storage tank.
23. The reduction system of claim 19, wherein a protection plate is
provided adjacent to the outlet of the plasma reactor in the
tailpipe to block crosswind of the exhaust gas.
24. The reduction system of claim 23, wherein the protection plate
is located at an upstream side of the exhaust gas before the outlet
of the plasma reactor.
25. The reduction system of claim 19, further comprising a third
fuel injector fitted to a third fuel inlet formed on the tailpipe
at a position corresponding to the plasma reactor.
26. The reduction system of claim 19, wherein the inflow hole is
formed on the inner surface of the reaction chamber to skew off at
an angle to a normal line of the inner surface of the reaction
chamber, wherein mixed fuel formed by mixing gas and fuel in the
mixing chamber flows into the reaction chamber through the inflow
hole while forming a rotational flow and circulates around a
circumference of the electrode.
27. The reduction system of claim 19, wherein a heat exchanging
conduit is formed in a wall body of the reaction chamber to
communicate the gas inlet with the mixing chamber, the heat
exchanging conduit being spiral in form along a circumference of
the reaction chamber.
28. A reduction system for particulate materials in exhaust gas,
which is connected to a tailpipe of an engine that burns a
hydrocarbon-based fuel supplied from a fuel storage tank, and
collects and removes particulate materials in the exhaust gas, the
reduction system comprising: a plasma reactor including a reaction
chamber having a gas inlet and an outlet, and an electrode having a
heating chamber formed therein, the electrode protruding into
reaction chamber; and a DPF (diesel particulate filter) trap having
a filter, wherein the tailpipe of the engine communicates with the
DPF trap and the outlet of the plasma reactor communicates with the
tailpipe that connects the engine and the DPF trap, wherein the
plasma reactor includes a fuel injector fitted to a fuel inlet that
is connected to the heating chamber of the electrode, the fuel
injector spraying and supplying liquid fuel into the heating
chamber, and wherein the electrode includes a spray nozzle through
which the inside of the reaction chamber is communicated with the
heating chamber.
29. The reduction system of claim 28, wherein the spray nozzle of
the electrode is formed to skew off at an angle to an exterior
surface of the electrode.
30. The reduction system of claim 28, wherein the plasma reactor
comprises a body including a reaction chamber and a base formed at
a lower end of the reaction chamber, the base including a mixing
chamber communicating with the gas inlet and communicating with the
reaction chamber through an inflow hole, wherein the electrode is
supported by the base.
31. The reduction system of claim 30, wherein the inflow hole is
formed on the inner surface of the reaction chamber to skew off at
an angle to a normal line of the inner surface of the reaction
chamber, and wherein mixed fuel formed by mixing gas and fuel in
the mixing chamber flows into the reaction chamber through the
inflow hole while forming a rotational flow and circulates around a
circumference of the electrode.
32. The reduction system of claim 30, wherein a heat exchanging
conduit is formed in a wall body of the reaction chamber to
communicate the gas inlet with the mixing chamber, the heat
exchanging conduit being spiral in form along a circumference of
the reaction chamber.
33. A plasma reactor comprising: a body including a reaction
chamber having a gas inlet and an outlet and a base formed at a
lower end of the reaction chamber, the base including a mixing
chamber communicating with the gas inlet and communicating with the
reaction chamber through an inflow hole; an electrode protruding
into the reaction chamber while being supported by the base and
being spaced apart from the inner surface of the reaction chamber,
the electrode having a heating chamber communicating with the
mixing chamber therein; a first fuel injector fitted to a first
fuel inlet formed on the base of the body and spraying and
supplying liquid fuel into the heating chamber; and a second fuel
injector fitted to a second fuel inlet connected to the reaction
chamber and spraying and supplying liquid fuel into the reaction
chamber.
34. The plasma reactor of claim 33, wherein the second fuel
injector is fitted to skew off at an angle to an inner surface of
the reaction chamber on a side of the reaction chamber, and sprays
and supplies liquid fuel above the electrode inside the reaction
chamber.
35. The plasma reactor of claim 33, wherein the first fuel injector
and the second fuel injector are connected to the fuel storage
tank.
36. The plasma reactor of claim 33, wherein the inflow hole is
formed on an inner surface of the reaction chamber to skew off at
an angle to a normal line of the inner surface of the reaction
chamber, wherein mixed fuel formed by mixing gas and fuel in the
mixing chamber flows into the reaction chamber through the inflow
hole while forming a rotational flow and circulates around a
circumference of the electrode.
37. The plasma reactor of claim 33, wherein a heat exchanging
conduit is formed in a wall body of the reaction chamber to
communicate the gas inlet with the mixing chamber, the heat
exchanging conduit being spiral in form along a circumference of
the reaction chamber.
38. A plasma reactor comprising: a body including a reaction
chamber having a gas inlet and an outlet and a base formed at a
lower end of the reaction chamber, the base including a mixing
chamber communicating with the gas inlet and communicating with the
reaction chamber through an inflow hole; an electrode protruding
into the reaction chamber while being supported by the base and
being spaced apart from the inner surface of the reaction chamber,
the electrode having a heating chamber communicating with the
mixing chamber therein; and a fuel injector fitted to a fuel inlet
formed on the base of the body, the fuel injector spraying and
supplying liquid fuel into the heating chamber, wherein the
electrode includes a spray nozzle through which the inside of the
reaction chamber communicates with the heating chamber.
39. The plasma reactor of claim 38, wherein the spray nozzle of the
electrode is formed to skew off at an angle to a surface of the
electrode.
40. The plasma reactor of claim 38, wherein the inflow hole is
formed on the inner surface of the reaction chamber to skew off at
an angle to a normal line of the inner surface of the reaction
chamber, wherein mixed fuel formed by mixing gas and fuel in the
mixing chamber flows into the reaction chamber through the inflow
hole while forming a rotational flow and circulates around a
circumference of the electrode.
41. The plasma reactor of claim 38, wherein a heat exchanging
conduit is formed in a wall body of the reaction chamber to
communicate the gas inlet with the mixing chamber, the heat
exchanging conduit being spiral in form along a circumference of
the reaction chamber.
Description
TECHNICAL FIELD
[0001] The present invention relates to an exhaust gas
after-treatment system of a vehicle, and more particularly relates
to a plasma reactor and a reduction system for particulate
materials within exhaust gas, in which the reactor and the system
may serve to oxidize and effectively remove the particulate
materials by heating the exhaust gas before a filter in a diesel
particulate filter (DPF) trap for removing particulate materials of
exhaust gas exhausted from an engine.
BACKGROUND ART
[0002] Particulate materials (PM) within exhaust gas of a vehicle
are mainly exhausted from diesel engines that generally control
power output by a mixing ratio of air and fuel. Diesel engines
increase fuel supply with respect to a quantity of air and burn the
fuel when instantaneous high power is needed. When this occurs, a
large amount of vehicle exhaust pollutants may be generated by
incomplete combustion of the fuel due to a shortage of air.
Further, during combustion in a diesel engine, a locally dense
amount of PM may appear since the time of spraying fuel into a
combustion chamber is extremely quick compared to a resultant
increase in intake air quantity, and thus a large amount of vehicle
exhaust pollutants may be generated. Generally, PM has a minute
diameter and includes a large amount of soluble organic materials
in addition to carbon particles. Research into human body hazards
is currently proceeding based upon recent reports of this being a
factor of lung cancer.
[0003] DPF traps use a technology of collecting and burning PM that
is exhausted from diesel engines, and can reduce PM by more than
80%. However, the technology has drawbacks of high cost and
uncertainty of durability. Technology of DPF traps is mainly
classified as collecting PM, and regenerating and controlling
technology.
[0004] DPF trap methods are classified as active regeneration
methods and passive regeneration methods according to the method of
burning PM during a regeneration process. The active regeneration
method actively applies heat for regeneration using an electric
heater, a burner, or a throttle, and the passive regeneration
method regenerates a filter with additives or oxidation catalysts
using the heat of the exhaust gas. Since a vehicle that is
primarily city driven emits exhaust gas of a low temperature, and
thus cannot obtain desired performance with only a passive
regeneration method, a combination method using both active
regeneration and passive regeneration is currently generally
adopted.
[0005] The DPF technology of the passive regeneration method lowers
the passive regeneration temperature of PM from 650.degree. C. to
300.degree. C. using catalysts or additives. However, the passive
regeneration method is difficult to apply directly to city buses
since city buses run at a low speed and stop often, and thus the
temperature of the exhaust gas is low or usually below 250.degree.
C. The method is also difficult to apply to mid-size or small
diesel vehicles of which the temperature of the exhaust gas is low
in the range of from 150.degree. C. to 200.degree. C.
[0006] When the active regeneration method is applied using an
electric heater, the cost of required electric power becomes
excessively high. When the active regeneration method is applied
using a burner that has a simple structure, it is difficult to
control the operation according to the condition of oxygen within
the exhaust gas, which varies depending on operating conditions
since the burner uses oxygen within the exhaust gas. The method of
throttling or injecting fuel additives lowers the oxidation
temperature of PM at the catalyst, but the method needs a device
for throttling on the intake/exhaust pipe and has a possibility of
secondary contamination by the additives.
DISCLOSURE
Technical Problem
[0007] The present invention provides a particulate material
reduction system in which a promptly operating plasma reactor
applies heat to exhaust gas proceeding toward a filter of a DPF
trap for removing particulate materials in exhaust gas from an
engine, and thereby the filter may oxidize and remove the collected
particulate materials promptly and effectively.
[0008] The present invention also provides a particulate material
reduction system in which liquid fuel supplied from a fuel storage
tank is transferred to a filter section after being reformed to
pre-oxidation materials that can be oxidized at the filter in
advance by a plasma reactor, and thereby causing good conditions
for oxidation of the collected particulate materials, such that the
oxidation of the particulate materials can be facilitated
effectively.
[0009] The present invention also provides a particulate material
reduction system in which a structure of a plasma reactor is
reformed to improve the mixibility of gas and liquid supplied, and
thereby operational reliability of the overall system is
ensured.
[0010] The present invention also provides a particulate material
reduction system in which a plasma reactor stably guides a flame
created by liquid fuel that is sprayed and supplied into the plasma
reactor and heats up exhaust gas, and thereby the heated exhaust
gas is supplied to a filter such that oxidation catalysts of the
filter may oxidize and burn accumulated particulate materials and
may cause good conditions for regeneration of the filter.
[0011] The present invention also provides a particulate material
reduction system in which liquid fuel is sprayed and supplied to a
flame formed from a plasma reactor, and thereby evaporated fuel is
immediately and continually supplied to a filter such that
oxidation catalysts of the filter may oxidize and heat the
evaporated fuel and may cause good conditions for regeneration of
particulate materials.
Technical Solution
[0012] According to an exemplary embodiment of the present
invention, a reduction system for particulate materials in exhaust
gas, which is connected to a tailpipe of an engine that burns a
hydrocarbon-based fuel supplied from a fuel storage tank, and
collects and removes particulate materials within the exhaust gas,
may include a plasma reactor having a gas inlet and an outlet, and
a DPF (diesel particulate filter) trap having a filter.
[0013] The tailpipe of the engine may communicate with the gas
inlet of the plasma reactor, and the outlet of the plasma reactor
may communicate with the DPF trap. The exhaust gas exhausted from
the engine may be transferred to the DPF trap after being heated
while passing through the plasma reactor.
[0014] The plasma reactor may include a body including a reaction
chamber having the gas inlet and the outlet and a base formed at
the lower end of the reaction chamber, the base including a mixing
chamber communicating with the gas inlet and communicating with the
reaction chamber via an inflow hole, and an electrode protruding
inside the reaction chamber while being supported by the base and
being spaced apart from the inner surface of the reaction
chamber.
[0015] A fuel inlet may be formed on the base of the body and a
heating chamber may be formed inside the electrode, the heating
chamber communicating with the mixing chamber and the fuel inlet
being connected to the heating chamber. A fuel injector may be
provided to the fuel inlet, the fuel injector being fixed on the
base of the body.
[0016] A heat exchanging conduit may be formed in a wall body of
the reaction chamber to communicate the gas inlet with the mixing
chamber, the heat exchanging conduit being spiral in form along a
circumference of the reaction chamber.
[0017] The inflow hole may be formed on the inner surface of the
reaction chamber to skew off at an angle to a normal line of the
inner surface of the reaction chamber, wherein mixed fuel formed by
mixing gas and fuel in the mixing chamber flows into the reaction
chamber through the inflow hole while forming a rotational flow and
circulates around a circumference of the electrode.
[0018] According to another exemplary embodiment of the present
invention, the tailpipe of the engine may be branched off and
communicated with the DPF trap and the inlet for gas of the plasma
reactor, respectively, and the outlet of the plasma reactor may be
communicated with the tailpipe that connects the engine and the DPF
trap. A part of the exhaust gas exhausted from the engine may be
transferred to the DPF trap after being heated while passing
through the plasma reactor.
[0019] The plasma reactor may have a fuel inlet and the fuel inlet
may be connected to the fuel storage tank. Fuel injected through
the fuel inlet may be plasma-reacted in the reaction chamber
together with the exhaust gas flowing in through the gas inlet,
such that the fuel may be reformed to a pre-oxidation material that
may be oxidized at a relatively low temperature in comparison with
the exhaust gas, or burned to raise the temperature of the exhaust
gas, and may be transferred to the DPF trap. The pre-oxidation
material may include hydrogen or carbon monoxide.
[0020] A fuel supply conduit fixed to the base of the body may be
fitted to the fuel inlet, and a gas supply conduit may be fitted to
a side of the fuel supply conduit to communicate therewith, thereby
spraying the fuel supplied through the fuel supply conduit into the
heating chamber with the gas supplied through the gas supply
conduit.
[0021] According to yet another exemplary embodiment of the present
invention, the tailpipe of the engine may communicate with the DPF
trap, and the outlet of the plasma reactor may communicate with the
tailpipe that connects the engine and the DPF trap.
[0022] The plasma reactor may have a fuel inlet and the fuel inlet
may be connected to the fuel storage tank. Fuel injected through
the fuel inlet may be plasma-reacted in the reaction chamber, such
that the fuel may be reformed to a pre-oxidation material that may
be oxidized at a relatively low temperature in comparison with the
exhaust gas, or burned to raise the temperature of the exhaust gas,
and is transferred to the DPF trap.
[0023] According to yet another exemplary embodiment of the present
invention, the tailpipe of the engine may communicate with the DPF
trap, and the outlet of the plasma reactor may communicate with the
tailpipe that connects the engine and the DPF trap. The plasma
reactor may include a first fuel injector being fitted to a first
fuel inlet formed on the base of the body and spraying liquid fuel
into the mixing chamber, and a second fuel injector being fitted to
a second fuel inlet connected to the reaction chamber and spraying
liquid fuel into the reaction chamber.
[0024] A heating chamber may be formed inside the electrode, the
heating chamber communicating with the mixing chamber and the first
fuel inlet being connected to the heating chamber, such that the
first fuel injector may spray liquid fuel into the heating chamber.
The second fuel injector may be fitted to skew off at an angle to
the inner surface of the reaction chamber on the side thereof, and
may spray and supply liquid fuel above the electrode inside the
reaction chamber. The first fuel injector and the second fuel
injector may be connected to the fuel storage tank.
[0025] A protection plate may be provided adjacent to the outlet of
the plasma reactor in the tailpipe to block a crosswind of the
exhaust gas. The protection plate may be located upstream of the
exhaust gas flow, before the outlet of the plasma reactor.
[0026] The reduction system may further include a third fuel
injector fitted to a third fuel inlet formed on the tailpipe at a
position corresponding to the plasma reactor.
[0027] According to yet another exemplary embodiment of the present
invention, the tailpipe of the engine may communicate with the DPF
trap, and the outlet of the plasma reactor may communicate with the
tailpipe that connects the engine and the DPF trap. The plasma
reactor may include a fuel injector fitted to a fuel inlet that may
be connected to the heating chamber of the electrode, the fuel
injector spraying and supplying liquid fuel into the heating
chamber. The electrode may include a spray nozzle through which the
inside of the reaction chamber may communicate with the heating
chamber.
[0028] The spray nozzle of the electrode may be formed to skew off
at an angle to an exterior surface of the electrode.
ADVANTAGEOUS EFFECTS
[0029] According to first to third exemplary embodiments of the
present invention, a promptly operating plasma reactor applies heat
to exhaust gas proceeding toward a filter of a DPF trap for
removing particulate materials in exhaust gas from an engine, and
thereby the filter can oxidize and remove the collected particulate
materials promptly and effectively.
[0030] Further, according to the first to third exemplary
embodiments of the present invention, liquid fuel supplied from a
fuel storage tank is transferred to a DPF trap after being reformed
to pre-oxidation materials mainly composed of hydrogen and carbon
monoxide, which can be oxidized at the DPF trap in advance or
burned by a plasma reactor, and thereby developing beneficial
conditions for oxidation of the collected particulate materials
such that the oxidation of the particulate materials can be
facilitated effectively.
[0031] Further, according to the first to third exemplary
embodiments of the present invention, the plasma reactor has a
reformed structure to improve the mixibility of supplied gas and
liquid, and thereby the operational reliability of the overall
system can be ensured.
[0032] According to a fourth exemplary embodiment of the present
invention, although there is a composition and temperature
variation of the exhaust gas depending on operational conditions, a
flame created by liquid fuel sprayed into the plasma reactor can be
stably maintained, and thereby there is no variation of performance
under load and dependence of the performance of the plasma burner
according to the load condition is drastically reduced, and further
the equipment of the device and the operational condition can be
simplified.
[0033] Further, the plasma reactor can stably maintain evaporation
performance regardless of a compositional condition of the gas and
the fuel, and thus it can increase the limits beyond the
conventional method using a burner.
[0034] The plasma reactor of the present invention is particularly
outstanding in atomization characteristics of liquid fuel,
evaporation characteristics, and mixing characteristics with an
oxidizing agent such that it can advance the technology of
reduction of particulate materials.
[0035] According to fifth to seventh exemplary embodiments of the
present invention, the plasma reactor can be simplified by forming
a spraying nozzle on an electrode to spray fuel, and the plasma
reactor enables the fuel to be evaporated directly at the electrode
and transferred to a mixing chamber, and thereby a large amount of
flowing fuel can be evaporated and thoroughly burned.
[0036] Because of the reduction system, noxious materials such as
unburned hydrocarbons that are normally exhausted while cold
starting without treatment due to low temperature can be removed,
and the previously equipped after-treatment device can operate
successfully even in a low-temperature condition such as city
driving.
[0037] As a result, by the above-mentioned effects, the particulate
materials within the exhaust gas, which are a factor of
environmental pollution, can be removed effectively, and thus the
ultimate goal of environmental pollution alleviation can be
accomplished.
DESCRIPTION OF DRAWINGS
[0038] FIG. 1 is a schematic diagram of a particulate material
reduction system according to a first exemplary embodiment of the
present invention.
[0039] FIG. 2 is a schematic diagram of a particulate material
reduction system according to a second exemplary embodiment of the
present invention.
[0040] FIG. 3 is a schematic diagram of a particulate material
reduction system according to a third exemplary embodiment of the
present invention.
[0041] FIG. 4 is a cross-sectional view of a plasma reactor applied
to the first through third exemplary embodiments of the present
invention.
[0042] FIG. 5 is a perspective view of the plasma reactor applied
to the first through third exemplary embodiments of the present
invention, which illustrates the shape of a heat exchanging
conduit.
[0043] FIG. 6 is a cross-sectional view taken along an A-A line of
FIG. 4, which illustrates the shape of an inflow hole.
[0044] FIG. 7 is a schematic diagram of a particulate material
reduction system according to a fourth exemplary embodiment of the
present invention.
[0045] FIG. 8 is a cross-sectional view of a plasma reactor applied
to the fourth exemplary embodiment of the present invention.
[0046] FIG. 9 is a partial cross-sectional view illustrates the
plasma reactor shown in FIG. 8 having a second fuel injector.
[0047] FIG. 10 is a cross-sectional view of the particulate
material reduction system according to the fourth exemplary
embodiment of the present invention, which illustrates a type of
plasma reactor connected to a connection tailpipe.
[0048] FIG. 11 is a cross-sectional view of the particulate
material reduction system according to the fourth exemplary
embodiment of the present invention, which illustrates another type
of plasma reactor connected to a connection tailpipe, with a
protection plate formed therein.
[0049] FIG. 12 is a schematic diagram of a particulate material
reduction system according to a fifth exemplary embodiment of the
present invention.
[0050] FIG. 13 is a schematic diagram of a particulate material
reduction system according to a sixth exemplary embodiment of the
present invention.
[0051] FIG. 14 is a plan view of the electrode of the plasma
reactor shown in FIG. 13, which illustrates the position and shape
of spraying nozzles.
[0052] FIG. 15 is a cross-sectional view of the particulate
material reduction system according to the fifth exemplary
embodiment of the present invention, which illustrates a type of
plasma reactor connected to a connection tailpipe.
[0053] FIG. 16 is a schematic diagram of a particulate material
reduction system according to a sixth exemplary embodiment of the
present invention.
[0054] FIG. 17 is a cross-sectional view of the particulate
material reduction system according to a seventh exemplary
embodiment of the present invention, which illustrates a type of
plasma reactor connected to a connection tailpipe, with a
protection plate formed therein.
BEST MODE
[0055] Hereinafter, the present invention will be described more
fully with reference to the accompanying drawings, in which
exemplary embodiments of the invention are shown. The invention
may, however, be embodied in different forms and should not be
construed as limited to the embodiments set forth herein. To
clearly describe embodiments of the present invention, parts not
related to the description are omitted, and like reference numerals
designate like elements throughout the specification.
[0056] FIG. 1 is a schematic diagram of a particulate material
reduction system according to a first exemplary embodiment of the
present invention.
[0057] As shown in FIG. 1, a particulate material reduction system
100 according to the present embodiment includes a diesel
particulate filter (DPF) trap that is connected to a tailpipe 140
of an engine 20 that burns a hydrocarbon-based fuel supplied from a
fuel storage tank 10, and collects and removes particulate
materials within exhaust gas, such that the reduction system
constitutes an exhaust gas after-treatment system. Further, the
particulate material reduction system 100 includes a plasma reactor
150 having a gas inlet 163 and an outlet 162, and the DPF trap 30
includes an oxidation catalyst 32 and a filter 35. The present
embodiment illustrates the DPF trap 30 having the oxidation
catalyst 32 as an example, but the particulate material reduction
system of the present invention may be realized without an
oxidation catalyst and may still expect the effects pursued by the
present invention. The following applies to all exemplary
embodiments below.
[0058] The tailpipe 140 of the engine 20 is connected to the gas
inlet 163 of the plasma reactor 150, and the outlet 162 of the
plasma reactor 150 is connected to the DPF trap 30. Exhaust gas
exhausted from the engine 20 is transferred to the DPF trap 30
after being heated while passing through the plasma reactor
150.
[0059] The caliber of the outlet 162 of the plasma reactor 150 may
be formed to be the same or close to that of the tailpipe 140, but
in FIG. 1 the caliber of the outlet 162 is illustrated to be larger
than that of the tailpipe 140 for convenience of explanation. This
also applies to the other drawings below.
[0060] In the present embodiment, the plasma reactor 150 is
provided in a route of the exhaust gas as it is transferred from
the engine 20 to the DPF trap 30. The plasma reactor 150 reacts
plasma with the supplied exhaust gas and exhausts the resultant
toward the DPF trap 30 section, and the exhaust gas that is
transferred to the DPF trap 30 is heated by the plasma reaction.
Accordingly, a condition of a high temperature for oxidation may be
maintained when the exhaust gas is oxidized at the oxidation
catalyst 32 of the DPF trap 30.
[0061] In the present embodiment, the entire quantity of the
exhaust gas transferred from the engine 20 to the DPF trap 30
through the tailpipe 140 is passed through the plasma reactor 150.
Further, the plasma reactor 150 may further include a fuel inlet
176 connected to the fuel storage tank 10, through which a liquid
fuel may be supplied into the plasma reactor 150. The fuel injected
through the fuel inlet 176 is plasma-reacted in the reaction
chamber 161 with the exhaust gas having flowed through the gas
inlet 163 and is partly reformed to pre-oxidation materials, which
may be oxidized at a relatively low temperature in comparison with
the exhaust gas, or burned, and is then transferred to the DPF trap
30.
[0062] FIG. 2 is a schematic diagram of a particulate material
reduction system according to a second exemplary embodiment of the
present invention.
[0063] As shown in FIG. 2, a particulate material reduction system
200 according to the present embodiment includes a DPF trap that is
connected to a tailpipe 240 of an engine 20 that burns a
hydrocarbon-based fuel supplied from a fuel storage tank 10, and
collects and removes particulate materials within exhaust gas, such
that the reduction system constitutes an exhaust gas
after-treatment system. Further, the particulate material reduction
system 200 includes a plasma reactor 150 having a gas inlet 163 and
an outlet 162, and a DPF trap 30 having an oxidation catalyst 32
and a filter 35.
[0064] The tailpipe 240 of the engine 20 is connected to the DPF
trap 30, a first branch line 241 branched from the tailpipe 240 is
connected to the gas inlet 163 of the plasma reactor 150, and the
outlet 162 of the plasma reactor 150 is connected to the tailpipe
240 connecting the engine 20 and the DPF trap 30 via a second
branch line 243. A part of the exhaust gas exhausted from the
engine 20 is transferred to the DPF trap 30 after being heated
while passing through the reaction chamber 161 of the plasma
reactor 150.
[0065] The plasma reactor 150 includes a fuel inlet 176, and the
fuel inlet 176 is connected to the fuel storage tank 10. The fuel
injected through the fuel inlet 176 is plasma-reacted in the
reaction chamber 161 with the exhaust gas having flowed through the
gas inlet 163 and is partly reformed to pre-oxidation materials,
which may be oxidized at a relatively low temperature in comparison
with the exhaust gas, or burned, and is then transferred to the DPF
trap 30.
[0066] In the present embodiment, the plasma reactor 150 is
provided in a route of the exhaust gas as it is transferred from
the engine 20 to the DPF trap 30. The plasma reactor 150 may be
supplied with a part of the exhaust gas and with hydrocarbon-based
fuel from the fuel storage tank 10 at the same time. Accordingly,
the exhaust gas supplied to the plasma reactor 150 is heated by the
plasma reaction, and the fuel supplied together with the exhaust
gas is partly reformed to pre-oxidation materials while being
plasma-reacted with oxygen (O.sub.2) within the exhaust gas. Such
pre-oxidation materials may contribute to an increased temperature
by oxidation and heat emission at a relatively low temperature at
the oxidation catalyst, where the pre-oxidation materials may be
obtained by reforming the hydrocarbon-based fuel supplied to the
plasma reactor 150 and the oxygen within the exhaust gas. Examples
of pre-oxidation materials are hydrogen (H.sub.2) and carbon
monoxide (CO), and a composition ratio of these materials can be
controlled by changing a mixing ratio of air and fuel.
[0067] The pre-oxidation materials created as in the above are
transferred to the DPF trap 30, and then supplies heat to the
section of the oxidation catalyst 32 of the DPF trap 30 by
oxidation.
[0068] In other words, in the present embodiment, a part of the
exhaust gas is used to burn fuel by plasma discharge while passing
through the plasma reactor 150 or transferred to the DPF trap 30
while maintaining such state to heat the oxidation catalyst 32
section. At the same time, pre-oxidation materials, which are
created by reforming the hydrocarbon-based fuel supplied to the
plasma reactor 150 with the oxygen within the exhaust gas, are
transferred to the DPF trap 30 and are oxidized at the oxidation
catalyst 32 in advance. Accordingly, the filter 35 can be
regenerated by burning and removing the particulate materials
collected in the filter 35 while heating the oxidation catalyst 32
section at an appropriate temperature for oxidation of the
particulate materials.
[0069] FIG. 3 is a schematic diagram of a particulate material
reduction system according to a third exemplary embodiment of the
present invention.
[0070] As shown in FIG. 3, a particulate material reduction system
300 according to the present embodiment includes a DPF trap that is
connected to a tailpipe 340 of an engine 20 that burns a
hydrocarbon-based fuel supplied from a fuel storage tank 10, and
collects and removes particulate materials within exhaust gas, such
that the reduction system constitutes an exhaust gas
after-treatment system. Further, the particulate material reduction
system 300 includes a plasma reactor 150 having a gas inlet 163 and
an outlet 162, and a DPF trap 30 having an oxidation catalyst 32
and a filter 35.
[0071] The tailpipe 340 of the engine 20 is connected to the DPF
trap 30, and the outlet 162 of the plasma reactor 150 is connected
to the tailpipe 340 that connects the engine 20 and the DPF trap
30. The plasma reactor 150 includes a fuel inlet 176, and the fuel
inlet 176 is connected to the fuel storage tank 10.
[0072] Hence, the fuel injected through the fuel inlet 176 is
plasma-reacted in the reaction chamber 161 and is reformed to
pre-oxidation materials, which may be oxidized at a relatively low
temperature in comparison with the exhaust gas, or burned, and is
then transferred to the DPF trap 30.
[0073] In the present embodiment, the outlet 162 of the plasma
reactor 150 is provided to a route of the exhaust gas as it is
transferred from the engine 20 to the DPF trap 30. The plasma
reactor 150 reforms the hydrocarbon-based fuel supplied from the
fuel storage tank 10 to pre-oxidation materials that can be
oxidized at a low temperature, by plasma reaction.
[0074] Oxygen or air required for reformation of the
hydrocarbon-based fuel needs to be supplied to the plasma reactor
150 simultaneously, and such function can be accomplished by the
gas inlet 163. Gas supplied from the outside is flowed in through
the gas inlet 163, and for example, oxygen (O.sub.2) or air
including oxygen may be flowed in as an oxidizing agent for
oxidation of the liquid fuel.
[0075] Pre-oxidation materials created through the plasma reactor
150 are transferred to the DPF trap 30 through the outlet 162 and
oxidized first at the oxidation catalyst 32, and thereby the
oxidation catalyst 32 section can be heated to an appropriate
temperature for oxidation of the accumulated particulate materials
of the exhaust gas.
[0076] The plasma reactor applied to the above exemplary
embodiments needs to ensure prompt and effective mixing of the gas
and liquid that flow in, and such function can be accomplished by
including constitutions that will be explained in detail below.
[0077] FIG. 4 is a cross-sectional view of a plasma reactor applied
to the first through third exemplary embodiments of the present
invention, and FIG. 5 is a perspective view that illustrates the
shape of a heat exchanging conduit.
[0078] Referring to FIG. 4, the plasma reactor 150 includes a body
160 providing a space for mixing and reaction, and an electrode 170
that applies voltage for plasma discharge. The body 160 is composed
of a reaction chamber 161 and a base 165, and the electrode 170 is
supported by the base 165 and protrudes inside the reaction chamber
161.
[0079] The reaction chamber 161 is formed in a cylindrical shape
having an inner space therein, and a gas inlet 163 and an outlet
162 are formed thereon. The gas inlet 163 is for inflow of gases
such as air or exhaust gas, and the outlet 162 is for exhaust of
reacted materials after plasma reaction. The gas inlet 163 may be
formed to be open toward the side of the reaction chamber 161, and
the outlet 162 may be open toward a side opposite the base 165.
[0080] The base 165 is formed at the lower end of the reaction
chamber 161, and includes a mixing chamber 167 communicating with
the gas inlet 163 and communicating with the reaction chamber 161
through an inflow hole 168.
[0081] As shown in FIG. 5, a heat exchanging conduit 164 is formed
in a wall body of the reaction chamber 161 to communicate the gas
inlet 163 with the mixing chamber 167, the heat exchanging conduit
164 being spiral in form along a circumference of the reaction
chamber 161. The gas flowing in through the gas inlet 163 is
transferred along the heat exchanging conduit 164, and may absorb
heat transferred from the reaction chamber 161.
[0082] FIG. 6 is a cross-sectional view taken along an A-A line of
FIG. 4, which illustrates a shape of an inflow hole.
[0083] The inflow hole 168 is formed on the inner surface of the
reaction chamber 161 to skew off at an angle to a normal line of
the inner surface of the reaction chamber 161. Mixed fuel formed by
mixing gas and fuel in the mixing chamber 167 flows into the
reaction chamber 161 while forming a rotational flow and circulates
around a circumference of the electrode 170, thereby forming a kind
of swirl flow. The inflow hole 168 may be formed in plural at equal
intervals, such that the inner space of the reaction chamber 161
can be utilized efficiently.
[0084] The reaction chamber 161 and the base 165 may be formed
integrally, or may be assembled to each other after being
manufactured separately. The base 165 may include an insulator such
as ceramic to prevent electricity from flowing between the lower
end of the electrode 170 and the reaction chamber 161.
[0085] The electrode 170 is supported by the base 165, and
protrudes inside the reaction chamber 161 while being apart from
the inner surface of the reaction chamber 161. The electrode 170 is
formed in a shape of a cone, to which a high voltage is applied
when operated. Here, the reaction chamber 161 is grounded to
maintain a high voltage state between the electrode 170 and the
reaction chamber 161.
[0086] The plasma reactor 150 may include a fuel inlet 176, and the
fuel inlet 176 is connected to the fuel storage tank 10 and is
supplied with liquid fuel therethrough. The fuel inlet 176 is
formed on the base 165 of the body 160, and the electrode 170 has a
heating chamber 175 therein. The heating chamber 175 communicating
with a mixing chamber 167 may be connected to the fuel inlet
176.
[0087] A fuel injector 180 that includes a fuel supply conduit 181
and a gas supply conduit 182 in the present embodiment is fitted to
the fuel inlet 176. The fuel supply conduit 181 is fixed to the
base 165 of the body 160, and the gas supply conduit 182 is fitted
to a side of the fuel supply conduit 181 to communicate therewith,
thereby spraying the fuel supplied through the fuel supply conduit
181 into the heating chamber 175 with the gas supplied through the
gas supply conduit 181. The gas supplied through the gas supply
conduit 182 may be from an exterior source of supply or may be a
part of the exhaust gas. A conventional injector may alternatively
be applied to the fuel inlet 176 so as to spray the liquid fuel
directly.
[0088] The operation of the plasma reactor 150 formed as above will
be described in detail below.
[0089] The plasma reactor 150 is supplied with liquid fuel through
the fuel supply conduit 181, and at the same time air or exhaust
gas containing oxygen (O.sub.2) flows into the plasma reactor 150
through the gas inlet 182. Here, the air or exhaust gas flowing in
is transferred to the mixing chamber 167 in an activated state at
which the temperature is sufficiently elevated while passing the
heat exchanging conduit 164. Further, the liquid fuel that is
transferred to the heating chamber 175 of the electrode 170 through
the fuel supply conduit 181 is transferred again to the mixing
chamber 167 in an evaporated and activated state by absorbing heat
in the heating chamber 175. In the mixing chamber 167, the air or
exhaust gas transferred through the heat exchanging conduit 164 is
mixed with the evaporated fuel transferred from the heating chamber
175, and then the mixture flows into the inner space of the
reaction chamber 161 through the inflow hole 168.
[0090] As described above, the air or the exhaust gas and the
liquid fuel having flowed into the plasma reactor 150 flows into
the inner space of the reaction chamber 161 after being
sufficiently mixed in the mixing chamber 167. A wetting and coking
phenomenon of the liquid fuel can be avoided since the liquid fuel
is prevented from ejecting directly from the heating chamber 175 or
prevented from directly contacting the exterior surface of the
electrode 170. Further, the liquid fuel that is heated in the
heating chamber 175 is immediately mixed with air in the mixing
chamber 167, such that a phenomenon of liquefaction while
transferring may be inherently prevented.
[0091] Meanwhile, the mixed fuel including the fuel and the air (or
exhaust gas) supplied from the mixing chamber 167 into the reaction
chamber 161 through the inflow hole 168 may lead to a relatively
highly efficient plasma reaction based on volume according to the
distinctive structure of the inflow hole 168 and the electrode 170.
In accordance with the exemplary embodiments of the present
invention, the electrode 170 is formed in a shape of a cone, and
the inflow hole 168 is formed on the inner surface of the reaction
chamber 161 to skew off at an angle to a normal line of the inner
surface of the reaction chamber 161. Accordingly, the mixed fuel
flowing in through the inflow hole 168 circulates along the
circumference of the electrode 170 and generates a rotating arc,
thereby leading to continuous plasma reaction.
[0092] FIG. 7 is a schematic diagram of a particulate material
reduction system according to a fourth exemplary embodiment of the
present invention, and FIG. 8 is a cross-sectional view of a plasma
reactor applied to the fourth exemplary embodiment of the present
invention.
[0093] As shown in FIG. 7, a particulate material reduction system
400 according to the present embodiment includes a diesel
particulate filter (DPF) trap that is connected to a tailpipe 440
of an engine 20 that burns a hydrocarbon-based fuel supplied from a
fuel storage tank 10, and collects and removes particulate
materials within exhaust gas, such that the reduction system
constitutes an exhaust gas after-treatment system. Further, the
particulate material reduction system 400 includes a plasma reactor
250 having a gas inlet 263 and an outlet 262, and the DPF trap 30
having an oxidation catalyst 32 and a filter 35.
[0094] The tailpipe 440 of the engine 20 is connected to the DPF
trap 30, and the outlet 262 of the plasma reactor 250 is connected
to the tailpipe 440 that connects the engine 20 and the DPF trap
30. The plasma reactor 250 includes a first fuel inlet 281 and a
second fuel inlet 291 that are positioned respectively at the front
and back of an electrode 270, and the fuel inlets 281 and 291 are
connected to the fuel storage tank 10.
[0095] Referring to FIG. 8, the plasma reactor 250 includes a body
260 providing a space for mixing and reaction, and the electrode
270 that is applied with a voltage for plasma discharge. The body
260 includes a reaction chamber 261 and a base 265, and the
electrode 270 is supported by the base 265 and protrudes inside the
reaction chamber 261.
[0096] The reaction chamber 261 is formed in a cylindrical shape
having an inner space therein, and a gas inlet 263 and an outlet
262 are formed thereon. The gas inlet 263 is for inflow of gases
such as air or exhaust gas, and the outlet 262 is for exhaust of
reacted materials after plasma reaction. The gas inlet 263 may be
formed to be open toward the side of the reaction chamber 261, and
the outlet 262 may be open toward a side opposing the base 265.
[0097] The base 265 is formed at the lower end of the reaction
chamber 261, and includes a mixing chamber 267 communicating with
the gas inlet 263 and communicating with the reaction chamber 261
through an inflow hole 268.
[0098] A heat exchanging conduit 264 is formed in a wall body of
the reaction chamber 261 to communicate the gas inlet 263 with the
mixing chamber 267, the heat exchanging conduit 264 being spiral in
form along a circumference of the reaction chamber 261. The gas
having flowed in through the gas inlet 263 is transferred along the
heat exchanging conduit 264, and may absorb heat that is
transferred from the reaction chamber 261.
[0099] The inflow hole 268 is formed on the inner surface of the
reaction chamber 261 to skew off at an angle to a normal line of
the inner surface of the reaction chamber 261. Mixed fuel formed by
mixing gas and fuel in the mixing chamber 267 flows into the
reaction chamber 261 while forming a rotational flow and circulates
around a circumference of the electrode 270, thereby forming a kind
of swirl flow. The inflow hole 268 may be formed in plural at equal
intervals, such that the inner space of the reaction chamber 261
can be utilized efficiently.
[0100] The reaction chamber 261 and the base 265 may be formed
integrally, or may be assembled to each other after being
manufactured separately. The base 265 may include an insulator such
as ceramic to prevent electricity from flowing between the lower
end of the electrode 270 and the reaction chamber 261.
[0101] The electrode 270 is supported by the base 265, and
protrudes into the reaction chamber 261 while being apart from the
inner surface of the reaction chamber 261. The electrode 270 is
formed in a shape of a cone. The electrode 270 may have a neck at
the lower part so as to form a broader space for reaction between
the electrode 270 and the inner surface of the reaction chamber
261, thereby forming a congestion section of flame. The mixed fuel
rotatably supplied through the inflow hole 268 moves around the
circumference of the electrode 270 while forming a rotational flow
in the reaction space. In this way, the plasma generated in the
reaction space rotates therein to improve the plasma reaction
efficiency in comparison with the former with the same volume.
However, the electrode 270 may not have a neck, and the present
invention is not limited thereto.
[0102] Meanwhile, in the plasma reactor 250 of the present
embodiment, a first fuel inlet 276 is formed on the base 265 of the
body 260 and a second fuel inlet 278 is formed on the reaction
chamber 261. A first fuel injector 280 supplying liquid fuel into
the mixing chamber 267 is fitted to the first fuel inlet 276, and a
second fuel injector 290 supplying liquid fuel into the reaction
chamber 261 is fitted to the second fuel inlet 278.
[0103] The first fuel inlet 276 is connected to a heating chamber
275, such that the first fuel injector 280 may spray and supply
liquid fuel into the heating chamber 275. The sprayed liquid fuel
is supplied into the mixing chamber 267 after being heated by the
reaction chamber 261.
[0104] The second fuel injector 290 is fitted to skew at an angle
to the inner surface of the reaction chamber 261 on the side
thereof, and sprays and supplies liquid fuel above the electrode
270 inside the reaction chamber 261. Although it is not shown, the
second fuel injector 290 may be fitted perpendicularly to the inner
surface of the reaction chamber 261 on the side thereof.
[0105] FIG. 9 is a partial cross-sectional view illustrates the
plasma reactor shown in FIG. 8 having an additional fuel
injector.
[0106] The number of second fuel injectors 290 may be varied
depending upon the size of the reaction chamber 261. One or more of
the second fuel injectors 290 can be provided to the reaction
chamber 261, and more than two may be arranged radially at equal
intervals. In the present embodiment, as shown in FIG. 9, three of
the second fuel injectors 290 are disposed at equal intervals. The
liquid fuel, which is sprayed from the plurality of second fuel
injectors 290 arranged radially at equal intervals, can collide to
make smaller particles in the reaction chamber 261.
[0107] The second fuel injector 290 includes a second fuel supply
conduit 291 and a second gas supply conduit 292. The second fuel
supply conduit 291 is fixed on the base 265 of the body 260, and
the second gas supply conduit 292 is fitted to a side of the second
fuel supply conduit 291 while communicating therewith. The fuel
supplied through the second fuel supply conduit 291 can be sprayed
into the heating chamber 275 with the gas supplied through the
second gas supply conduit 292. The gas supplied through the second
gas supply conduit 292 may be from an exterior source of supply or
a part of the exhaust gas. A conventional injector may
alternatively be applied to the second fuel inlet 278 so as to
spray liquid fuel directly.
[0108] Meanwhile, the liquid fuel sprayed through the second fuel
injector 290 is burned to form a flame at the outlet 262 by the
electrode 270 that is applied with a high voltage and plasma formed
in the reaction chamber 261.
[0109] FIG. 10 is a cross-sectional view of the particulate
material reduction system according to the fourth exemplary
embodiment of the present invention, which illustrates a type of
plasma reactor connected to a connection tailpipe.
[0110] Referring to FIG. 10, a connection tailpipe 441 for the
plasma reactor 250 may be formed on the tailpipe 440 that connects
the engine 20 and the DPF trap 30. The connection tailpipe 441 has
a setting depression 443 that is depressed toward a central axis,
to which the outlet 262 of the plasma reactor 250 is connected.
[0111] FIG. 11 is a cross-sectional view of the particulate
material reduction system according to the fourth exemplary
embodiment of the present invention, which illustrates another type
of plasma reactor connected to a connection tailpipe, with a
protection plate formed therein.
[0112] A protection plate 447 may be provided adjacent to the
outlet 262 of the plasma reactor 250. The protection plate 447 is
coupled to a setting depression 446 formed on the connection
tailpipe 445 to protect the flame from a crosswind of the exhaust
gas. It is desirable for the protection plate 447 to be located
upstream of the exhaust gas flow before the outlet 262 of the
plasma reactor 250.
[0113] Meanwhile, a third fuel injector 480 is fitted to a third
fuel inlet 449 formed on a connection tailpipe 445 at a position
corresponding to the plasma reactor 250.
[0114] The third fuel injector 480 sprays liquid fuel to the flame
created at the plasma reactor 250 so as to supply gaseous fuel to
the oxidation catalyst 32 of the DPF trap 30. The liquid fuel
sprayed through the third fuel injector 480 is evaporated
immediately by the flame 230 to become the gaseous fuel, and then
the gaseous fuel is transferred to the oxidation catalyst 32 of the
DPF trap 30 along the tailpipe 440. The third fuel injector 480 is
connected to the fuel storage tank 10, and a conventional injector
or nozzle may be applied for the third fuel injector 480. The third
fuel injector 480 does not always need to be applied together with
the protection plate 447. The third fuel injector 480 can be
applied to the connection tailpipe 441 of FIG. 10, and further, it
can be fitted to the tailpipe 440.
[0115] The operation of the particulate material reduction system
according to the present embodiment will be described below,
referring to FIG. 7 and FIG. 8.
[0116] The gas (air or exhaust gas), that flows in through the gas
inlet 263 formed on a side of the reaction chamber 261 of the
plasma reactor 250, is supplied into the mixing chamber 267 formed
in the base 265, after being pre-heated while passing through the
heat exchanging conduit 264 formed on the reaction chamber 261.
[0117] The gas flowed into the mixing chamber 267 is mixed with the
liquid fuel supplied through the first fuel injector 280. That is,
the liquid fuel supplied through the first fuel injector 280 is
sprayed into the heating chamber 275 formed in the electrode 270,
and the sprayed liquid fuel is supplied to the mixing chamber 267
after being pre-heated in the heating chamber 275.
[0118] The mixed fuel that is mixed in the mixing chamber 267 is
supplied through the inflow hole 268 to form a rotational flow in
the reaction chamber 261. The mixed fuel supplied as such
circulates around a circumference of the electrode 270 to generate
a rotating arc, thereby leading to plasma induced flame. Here,
liquid fuel is supplied through the second fuel injector 290, and
the liquid fuel is burned to form a flame at the outlet 262 by a
high voltage applied to the electrode 270 and the plasma.
[0119] The flame may expand into the tailpipe 440 or the connection
tailpipe 441 or 445 through the outlet 262 and supply heat for the
exhaust gas transferred therethrough. If the exhaust gas is heated
as such, particulate materials (PM) contained within the exhaust
gas may be heated to a temperature at which the PM can be easily
reacted at the oxidation catalyst 32 of the DPF trap 30.
[0120] Meanwhile, if the third fuel injector 480 is applied to the
present embodiment, liquid fuel is sprayed to the flame formed at
the outlet 262 through the third fuel injector 480, and then the
liquid fuel is evaporated to contribute to an increase in
temperature by oxidation at the oxidation catalyst 32 of the DPF
trap 30.
[0121] FIG. 12 is a schematic diagram of a particulate material
reduction system according to a fifth exemplary embodiment of the
present invention, and FIG. 13 is a schematic diagram of a
particulate material reduction system according to a sixth
exemplary embodiment of the present invention.
[0122] As shown in FIG. 12, a particulate material reduction system
500 according to the present embodiment includes a DPF trap that is
connected to a tailpipe 540 of an engine 20 that burns a
hydrocarbon-based fuel supplied from a fuel storage tank 10, and
collects and removes particulate materials within exhaust gas, such
that the reduction system constitutes an exhaust gas
after-treatment system. Further, the particulate material reduction
system 500 includes a plasma reactor 350 having a gas inlet 363 and
an outlet 362, and a DPF trap 30 having an oxidation catalyst 32
and a filter 35.
[0123] The tailpipe 540 of the engine 20 is connected to the DPF
trap 30, and the outlet 362 of the plasma reactor 350 is connected
to the tailpipe 540 connecting the engine 20 and the DPF trap 30.
The plasma reactor 350 includes a fuel inlet 376 at the back of the
electrode 370, and the fuel inlet 376 is connected to the fuel
storage tank 10.
[0124] In the present embodiment, the electrode 370 includes a
spray nozzle 373 through which the inside of the reaction chamber
361 is communicated with the heating chamber 375. Referring to FIG.
14, the spray nozzle 373 of the electrode 370 is formed to skew off
at an angle to an exterior surface of the electrode 370. One or
more spray nozzles 373 may be provided to the electrode 370, and
more than two may be arranged radially at equal intervals.
[0125] When the plasma reactor 350 is operated, a high voltage may
be applied to the electrode 370. The fuel sprayed from the spray
nozzle 373 formed on the electrode 370 is burned by plasma
generated in the reaction chamber 361 to form a flame at the outlet
362.
[0126] Features of the present embodiment that have not been
described in detail or otherwise are similar to the plasma reactor
of the fourth exemplary embodiment.
[0127] FIG. 15 is a cross-sectional view of the particulate
material reduction system according to the fifth exemplary
embodiment of the present invention, which illustrates a type of
plasma reactor connected to a connection tailpipe.
[0128] Referring to FIG. 15, a connection tailpipe 541 for the
plasma reactor 350 may be formed on the tailpipe 540 that connects
the engine 20 and the DPF trap 30. The connection tailpipe 541 has
a setting depression 543 depressed toward a central axis, to which
the outlet 362 of the plasma reactor 350 is connected.
[0129] The operation of the particulate material reduction system
according to the present embodiment will be described below,
referring to FIG. 12 and FIG. 13.
[0130] The air that flows in through the gas inlet 363 formed on a
side of the reaction chamber 361 of the plasma reactor 350 is
supplied into the mixing chamber 367 formed in the base 365, after
being pre-heated while passing through the heat exchanging conduit
364 formed on the reaction chamber 361. The air having flowed into
the mixing chamber 367 is mixed with the liquid fuel supplied
through the fuel injector 380.
[0131] The liquid fuel supplied through the fuel injector 380 is
sprayed into the heating chamber 375 formed in the electrode 370,
and a part of the sprayed liquid fuel is supplied to the mixing
chamber 367 after being pre-heated in the heating chamber 375 while
and the rest is sprayed to the reaction chamber 361 through the
spray nozzle 373.
[0132] The mixed fuel that is mixed in the mixing chamber 367 is
supplied through the inflow hole 368 to form a rotational flow in
the reaction chamber 361. The mixed fuel supplied as such
circulates around a circumference of the electrode 370 to generate
a rotating arc, thereby leading to plasma. Here, liquid fuel is
supplied through the spray nozzle 373 of the electrode 370, and the
liquid fuel is burned to form a flame at the outlet 362 by a high
voltage applied to the electrode 370 and the plasma.
[0133] The flame may expand into the tailpipe 540 or the connection
tailpipe 541 through the outlet 362 and supply heat for the exhaust
gas transferred therethrough. If the exhaust gas is heated as such,
particulate materials (PM) contained within the exhaust gas may be
heated to a temperature at which the PM can be easily reacted at
the oxidation catalyst 32 of the DPF trap 30.
[0134] FIG. 16 is a schematic diagram of a particulate material
reduction system according to a sixth exemplary embodiment of the
present invention.
[0135] A particulate material reduction system 600 according to the
present embodiment is similar to that of the fifth exemplary
embodiment. However, exhaust gas flows into the plasma reactor 350
since the gas inlet 363 of the plasma reactor 350 is connected to
the tailpipe 640 of the engine 20.
[0136] FIG. 17 is a cross-sectional view of the particulate
material reduction system according to a seventh exemplary
embodiment of the present invention, which illustrates a type of
plasma reactor connected to a connection tailpipe, with a
protection plate formed therein.
[0137] In the plasma reactor 450 applied to the particulate
material reduction system 700 according to the present embodiment,
the electrode 470 includes a spray nozzle 473 through which an
inside of the reaction chamber 461 is communicated with the heating
chamber 475. In this way, the plasma reactor 450, which is similar
to the plasma reactor of the fourth exemplary embodiment, includes
fuel inlets 476 and 478 that are positioned respectively at the
front and back of the electrode 470. The fuel inlets 476 and 478
are provided with fuel injectors 480 and 490 connected to the fuel
storage tank, and liquid fuel can be sprayed into the heating
chamber 475 or the reaction chamber 461 therewith.
[0138] Meanwhile, a protection plate 747 may be provided adjacent
to the outlet 462 of the plasma reactor 450. The protection plate
747 is coupled to the setting depression 743 formed on the
connection tailpipe 741 to make the flame stable from a crosswind
of the exhaust gas.
[0139] While this invention has been described in connection with
what is presently considered to be practical exemplary embodiments,
it is to be understood that the invention is not limited to the
disclosed embodiments, but, on the contrary, is intended to cover
various modifications and equivalent arrangements included within
the spirit and scope of the appended claims.
* * * * *